1. Field of the Invention
The invention relates in general to a wireless sensor network, and more particularly to a wireless sensor network for dynamically adjusting detection behavior of sensors according to periodic property of sensed data.
2. Description of the Related Art
A wireless sensor network (WSN) may be applied to such as detection of forest ecology monitor, detection of the concentration of carbon dioxide in the factory, or the indoor monitor. In the wireless sensor network, a wireless sensor for sensing, collecting, and returning data plays an important role.
In the prior art, the wireless sensor detects environment variables and returns data according to a sense frequency (sense interval) specified by an administrator. When the sense interval is longer (sense times are fewer), more energy is saved but less sensed data is obtained. When the sense interval is shorter (the sense times are more), more sensed data may be obtained but the power-consumption could be greater. This is because the power consumption could be relatively great when the wireless sensor is in sensing or transceiving data. In addition, the wireless sensor is usually powered by a battery, and it is hard to charge the battery if in outdoor environment.
Thus, how to save the power consumption of the wireless sensor has become a very important issue. At present, the power-saving mechanism for the wireless sensor is emphasized on the power consumption in transmitting or sensing, but the effect is poor.
In view of this, it needs a data sensing method for analyzing the trend of data collected by the wireless sensor, and for dynamically adjusting the detection behavior (i.e., whether to sense or not) of the wireless sensor according to property of data period).